Rotary switches of the above-mentioned type are already frequently used as control devices incorporated together with other control and signalling units in control panels or desks, or in similar installations. In this case, the stack of molded wafers is generally fixed solely at one of its ends to a supporting element and must consequently have sufficient inherent strength and rigidity to withstand the stresses coming from the camshaft in order to guarantee perfect operation even after a long period in service.
In rotary wafer switches known heretofore, this strength and rigidity is obtained by taking the molded elements (which used to be made of porcelain and have more recently been made of plastic) and interconnecting them very stiffly by means of threaded rods passing through the entire stack and acting as draw rods. However, such mechanical connection is expensive in equipment and in labor, and then requires correct screw tightening to be guaranteed, which imposes subsequent verification in addition to special care during assembly.